There are many different variations of Linux, however at their heart they share a common kernel. They will all have slightly different kernel versions and different approaches and purposes. However broadly speaking they are generally compatible. A good summary is available at List of Linux distributions - Wikipedia, the free encyclopedia which also helps explain what is based on what. Distributions tend to fork from somewhere, or use an existing distribution as their starting point.

One of the key differentials between distributions is the update mechanism, specifically the software to do this, the package management system and the associated file format. Debian uses DEB files and Red Hat & SUSE were the original distributions using RPM files. A more obvious difference is the desktop being used, where GNOME and KDE are the most common, with others like Unity and Cinnamon gaining ground.

If you want an overview/comparison of all Linux Distributions, then head to DistroWatch.com: Put the fun back into computing. Use Linux, BSD. which specialises in this. You might want to use the DistroWatch.com: Major Distributions to limit your search. Below I have picked out some of the major distributions and made a comment on them, those that I have used and made some notes about will have a "See also" link for more detailed information.


The Fedora Project runs the community that produces Fedora, however Red Hat are very involved as they own the Fedora trademark and they produce their releases from versions of Fedora. According to Wikipedia Linus Torvalds uses Fedora. Security is important for Fedora and hence it uses Security Enhanced Linux.
See also Fedora

Red Hat

Often known as Red Hat, this is actually the company name, the commonly used product is Red Hat Enterprise Linux or RHEL, which is a paid for, supported, commercial distribution. Runs on Intel hardware as well as IBM Power and many others. Red Hat do run a developer programme, see No-Cost RHEL Developer Subscription now available – Red Hat Developer Blog for details.


The Community ENTerprise Operating System. This is based on Red Hat and is the community supported version of Red Hat and is generally in sync with RHEL. It does however not have any of the proprietary parts of Red Hat so that it can be freely distributed. If you want a free version of RHEL, then this is the best distribution to use.
See also CentOS

Oracle Linux

Based on Red Hat but fully supported by Oracle and aims to be Red Hat compatible, the support is paid for, although you can use it for free, unsupported. It is however good for running Oracle Databases and other Oracle products. Note that if you want a GUI, step 16 of ORACLE-BASE - Oracle Linux 6 Installation is essential!
See also Oracle Linux


There is an interesting history to this but suffice to say openSUSE is the free distribution and then SLES and SLED are paid for and supported. SLES is SUSE Linux Enterprise Server and then SLED is the desktop version. There are other variations, including SLE-POS, a "Point of Sale" or retail specialist version.
See also openSUSE


As one of the oldest distributions it is the basis for a lot of others. It is very popular with for use on web servers.


Built on Debian it has itself become the basis for several other distributions. It is largely funded by Canonical who will provide paid for support, although you can still get it for free.